style: replace upload-style share icon with two-person users icon across all views

frontend/src/features/help/HelpView.tsx

@@ -234,7 +234,7 @@ export const HelpView: React.FC<HelpViewProps> = () => {
             <div className="grid grid-cols-1 md:grid-cols-2 gap-3 text-xs">
               <div className="p-3 bg-canvas border border-border rounded-card space-y-2">
                 <h3 className="font-semibold text-main flex items-center gap-1.5">
-                  <Share2 className="w-3.5 h-3.5 text-accent" />
+                  <Users className="w-3.5 h-3.5 text-accent" />
                   <span>Aufgabenlisten teilen & Avatar-Stack</span>
                 </h3>
                 <p className="text-muted leading-relaxed">